Tebbitoey



` (No Model.)V Y Y 2 Sheets-Sheet 1.

\ N.: A. FOSS & J.M. GRAY. f

ROASTING FURNAGE.

Patented Feb. v5, 1.884.

INVBNTOR ATTGR s.

N. PETERS Pimxvutmgnphar, washlngiun. D. c.

2 Sheets-Sheet 2.

(No Mqdel.)

N.V A Poss & J. MGRAY.

ROASTING FURNAGE.

No. 293,002. Patented F8115, 1884.

INVENOR: 73,66. ,auf l ATTORNEYS.

UNTTED STATES.

Q PATENT OFFICE.

NEWMAN A. ross .NND JOHNM. GRAY, OF OLENDENIN, MONTANA TERRITORY.

RoAsrlNc-'FURNACB SPECIFICATION forming part of Letters Patent VNo. 293,002., dated February 5, 1884.

' Application filed September 11,1853. (No molhl.)

" To a/ZZ whom, it may concern:

which similar letters of reference indicate con' responding parts in all the figures.

i Figure lis a longitudinal sectional elevation of our improved furnace. Fig. `2 is a similar section of part of the tube and the feeding'apparatus on an enlarged scale. Fig.

-3 is a similar section through the reverberatory furnace and receiving-chamber and part of the tube,also on an enlargedseale. Fig. `4t is a transverse section on the line x av of Fig. 3, and Fig. 5 is atransverse section of the tube `on the line y y ofFig. l.

XVe arrangea long tube, a, between the receiving-chamber s and the chimney c, made in preferably fourA sections, which are suc! cessively smaller in diameter from the furnace to the chimney, forming inside ledges at the junctions, down whichuthe ore falls in passing from onesection to another. of the tube is made of boilerairon, and the sections are joined together bystrongs rings of cast-iron d, having an offset to correspond with the sizes of the two sections to be joined. The, inside 'is lined with fire-brick, and there are four spiral projecting ribs, c, of the same material, to feed theore along the tube. The brick of which ribs c are formed are set with their longitudinal projecting side faces in line with the axis of the cylinder, so that these faces form a .series of stepsl down which the ore falls for more complete exposure to the heat, as will readily be understood. The tube is mounted by ring-rails] on grooved rollers f/ for its support, and O11 which it 4is to be re volved by power applied to the pinion h, and working thetoothed rim 2, attached to the tube. The tube is arranged on a slight inclination 5o from the furnace np to the base of the flue c,

to be revolved by the tube.

The outside shell into which it discharges through the lateral opening j, in which there is a conveyor-tube, k, containing a screw, Z, the shaft of which is attached to a cross-bar, m, of the tube, so as From the upper end of said tube k therejs a spout 'extending up through the base of the due, to which the orc is delivered from the hopper o. The boxes 1) for the grooved roller-bearings are secured to the supporting-beds by bolts q, that are prolonged considerably aboveethe boxes, in order that the boxes may be raised and packed up p in case it may be desired to alter the inclination of the tube for varying the pitch to accelerate or retard the movement of the ore.

From the lower end of the tube the ore dis` charges into a receiving-chamber, s, lined with refractory material, and having an inclined hearth, t, onto which the ore falls.

each side, above the working-doors, is another door, o, to be opened, when required, to admit cold air to regulate the temperature in the tube. The front wall, opposite to the end ofthe tube, has another door, w, (dotted Fig. 3,) to admit cold air, and another door, w, is provided under the tube f or the same purpose.

The receiving-chamber s dischargesinto a reverberatory furnace, y, in which is a castiron pan, z, resting on brick or stone piers c, and lined with fire-brick bf, forming the fusing-hearth. `At each end of the pan is a castiron water-jacket, c, resting 1in the pan, and having the proper pipe-connections for main taining a circulation of water therein for the protection of the bridge-wall d and the back wall, e', `from the extreme heat. Back of the fuse-hearth, at f', there is an opening at each side for admitting the air for the furnace, to cause it to pass along under thepan for keeping it cool, and for heating the air for preparing it for more effectual combustion, the fuel-door g and the ash-pit door h being closed in order to cause the air to enter in this way. The arch of the reverberatory furnace is contracted at the end next the receiving-chamber, the object Of which is to bring the flame gradually nearer the fusing-hearth as it leaves the more heated part of the furnace, thus giving annito a line powder and mixed in suitable proportions for treatment, is taken to the hopper, from which it is conveyed into the cylinder or revolving` part of the furnace by the screwconveyer l, which turns with the cylinder. By

io the inclination of the cylinder each revolution advances the ore gradually from the cooler to the more heated part of the furnace. 'Vhen the ore has been raised sufficiently high on the lines of projecting tiles c, it falls off in finelydivided streams through the hot gases passing up the cylinder in such a way that no particle can escape full exposure to the oxidizing iniiuence required for proper cal cination. The ore having become sufficiently heated for the 2o expulsion of the sulphur, arsenic, and other metals capable of being separated by the combined action of heat and atmospheric air, and the substitution of oxygen for the metals so expelled, the ore arrives at the receivingchamber s in the best possible con-dition for treatment,presently to be described. The heat evolved by the combustion of the sulphur and arsenic assists in roasting the ore in the upper part of the cylinder. The receiving-chamber s is the receptaclefor the roasted ore coming from the cylinder. Here the ore is exposed to a much higher temperature, and the roasting is continued until the charge undergoing slagging in the reverberatory furnace is With- 3 5 drawn. Then the charge in the receiving-ch am ber is advanced by the workman, with tools applied through the workingdoors n, to the fusing-hearth b. During this operation the furnace-men regulate the heat in the receivingT 4o chamber and cylinder by opening or closing.

the doors c of the receiving-chamber, allowing the introduction of more or less cold air.

rlhe ore having reached the fusing-hearth,

fusing and agglomeration take place at once,

5 and the ore is withdrawn from the furnace through the working-doors a2 as a silicate of lead containing all the precious metals and in the best possible condition for subsequent treatment in the blast-furnace; or by raising 5o the working-doors a few inches above the fusing-hearth and providing the furnace with a tap forthe discharge of the slag and bullion and adding the necessary fiux, reduction will take place and the separation of the slag and bullion will be complete without further treatment. The flame, after doing its work in the reverberatory furnace and receiving-chamber,

roasts the ore in the cylinder, which serves furnace, giving a steady and constant feed;

the length of the cylinder giving the ore sufficient time for desulphurizing before arriving at the fusing-furnace, the diminishing form of the cylinder concentrating the heat in the flue end; the adjustable bearing arrangement, whereby the cylinder may have more or less inclination for passing the ore faster or slower through the cylinder as the ore needs more or less roasting; the constant agitation of thc ore effected by the projecting lines of tile in the cylinder keeping the ore constantly falling through the hot gases passing up the cylinder, the facility afforded for the escape of any metals reduced or slagged by the inclined hearth of the receiving-chamber into the reverberatory furnace; the facility of regulating the heat in the cylinder by allowing the introduction of cold air through the receivingchamber; the iron pan forming the bottom of' the reverberatory furnace arranged for not absorbing the fused metal and being more readily and easily repaired 5 the arrangement for allowing the cold air to pass under the furnace, keeping the bottom cool and warming the air before reaching the fuel; the greater economy of treatment by lessening the cost of stirring of the ore during roasting by the rolling of the tube, instead of by manual labor, the economy' of fuel by roasting and slagging at the same time and using the evolved gases to assist in roasting the ore.

Having thus described our invention, we 9 claim as new and desire to secure by Letters Patent- 1. In combination with the sections of tube a. the metallic bands or rings (l, offset to fit closely over the joint or junction of two adjacent sections, as shown and described.

2. The combination, with tube a, lined on the inside with refractory material, of spiral ribs formed of brick laid to make a success` sion of' steps, as and for thepurpose specified.

NEVMAN A. FOSS. JOHN M. GRAY.

\Vitnesses: V

JAMES WALLACE CALDWELL, W'ILLIAM CLEMEN'rs GU'rnRiE.

IOO 

